Divide. Write your answer in simplest form. $ -\dfrac{7}{9} \div \dfrac{9}{8} = {?} $
Solution: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{9}{8}$ is $\dfrac{8}{9}$. Therefore: $ -\dfrac{7}{9} \div \dfrac{9}{8} = -\dfrac{7}{9} \times \dfrac{8}{9} $ $ \phantom{-\dfrac{7}{9} \div \dfrac{9}{8}} = \dfrac{-7 \times 8}{9 \times 9} $ $ \phantom{-\dfrac{7}{9} \div \dfrac{9}{8}} = -\dfrac{56}{81} $